Sound-box for phonographs.



APPLICATION FILED AUG-5. 1915.

Patented Mar. 14, 1916.

1 UNITED STATES PATENT oFEioE JOSEPH G. KULP, OE ATLANTIC HIGHLANDS, NEW JERSEY.

SOUND-BOX FOR PHONOGRAPHS.

- a phonograph, and more specifically to an auxiliary diaphragm, located between the usual diaphragm, and the outlet to the am- This invention is an improvement on the auxiliary diaphragm disclosed in my application Serial No. 37904 filed July 3, 1915;

One object of this invention is to provide an auxiliary diaphragm of such material and construction, as will produce a more musical and softer tone.

A second object is to provide such a diaphragm as will produce a tone, amplified to a greater degree than is possible by the use of the usual diaphragm alone.

A third object is to provide such a diaphragm, as will produce better enunciation than heretofore attained.

A fourth object is to produce a wooden diaphragm which will vibrate substantially as well across the grain of the wood as with the grain.

I attain these objects by the mechanism illustrated in the accompanying drawing, in 'which- Figure 1 illustrates a sectional view through a phonograph sound box equipped with my auxiliary diaphragm. Fig. 2 illustrates a plan view'of one form of my improved diaphragm. Fig. 3 illustrates a plan view of a modified form of my improved diaphragm, and Fig. 4 illustrates a sectional view along line 4-4 of Fig. 3.

In the several views of the drawing, the same reference characters represent the same parts.

The sound box illustrated in Fig. 1 comprises a cylindrical casing 1, comprising a rim. section 2 and an end section 3. secured Specification of Letters Patent.

Application filed August 5, 1915.

Patented Mar. 14, 1916..

Serial No. 43,748.

Supported freely within the rim 2 of the casing is a diaphragm 9 of mica. or any other well known material and a wooden diaphragm 10, retained in position by means of rubber gaskets 11, between the inner face of the end section 3 of the casing, and the inturned flange 12, of the rim 2. To the center of the diaphragm 9 is attached the stylus bar 13. The stylus bar is of the usual construction, and a detailed description thereof is considered unnecessary herein.

One form of the auxiliary wooden diaphragm 10, is illustrated in detail in Fig. 2. I preferably construct it as a thin wafer of close grained hard wood provided with a small number of small equally spaced openings 14 adjacent its periphery. When a smooth thin wafer of wood is employed, the wood must be thoroughly seasoned and by natural processes. Kiln dried wood fails to give as satisfactory results as naturally' seasoned wood. The wood must be hard and close grained, cherryhaving been found the most satisfactory.

The holes 14, to give the best results must be as near the periphery of the diaphragm as possible and still have them uncovered'when the said diaphragm is clamped within the casing 2 between the gaskets 11. Further the holes must be equally spaced and few in number, four having been found productive of the best results. Holes placed nearer the center of the diaphragm and more nearly in alinement with the outlet 6 in the casing, failed to reduce to an appre.

ciable amount. the metallic tones produced by the mica diaphragm 9. The four holes as shown in Figs. 2 and 3 are generic to both modifications of my invention. Also these four holes in Figs. 2 and 3 were disclosed in my former application filed July 3, 1915, Serial No. 37.904.

Owing to the fact that the diaphragm, to

vibrate freely, must be very thin, a greatdeal of difficulty has been experienced in obtaining wood sufficiently thin, and yet strong enough for the purpose. I have found that highly satisfactory results may be obtained,

by constructing the diaphragm of thicker wood, and scoring it upon either side across the graln, as shown in Figs. 3 and 4. In

these figures I have disclosed a wooden diaphragm 10 provided with a plurality of holes 14 and scorings 25 running approxilately at right angles to the grain on either side, those upon one side alternating with those upon the other side. A diaphragm, thus constructed, vibrates freely throughout its surface, the scorings'serving to weaken the wood across the grain but not with the grain.

While i have shown four scorings upon one side of the diaphragm and three alternating with them on the opposite side of the diaphragm, I do not wish to be limited to the number, width, or depth of such scorings or grooves.

I have further discovered that a diaphragm constructed in accordance with Figs. 3 and a may be made from any suitable wood, special close 'rained, hard wood being unnecessary.

While I have illustrated my improved diaphragms as applied to a phonograph sound box, I do not'wish to be restricted to such specific use, as my diaphragms might be used in analogous arts, for instance in' telephone receivers and other sound producing instruments What I claim as my invention is 1. In a phonograph sound box'the cornbination with a casing, and a diaphragm therein supported. between rubber gaskets, of a thin wooden diaphragm therein having an iinperforate central portion and four equally spaced openings adjacent its periphery, said wooden diaphragm being mounted parallel to the first mentioned diaphragm and spaced therefrom by one of said gaskets.

2. A sound modifying plate adapted to be mounted within a sound box casing comprising a thin wooden member adjusted to fit such casing and having an imperforate central portion and four equally spaced openings adjacent'its periphery.

3. In a sound box fora phonograph, the combination with a casing, rubber gaskets within the casing and a diaphragm supported within the casing between said gaskets, of a thin wooden diaphragmprovided with four equally spaced openings adjacent its 361'] )herv and rooves in both ilane sur faces, cut across the grain of th wood, the grooves on one surface alternating with the grooves on the other surface, said wooden diaphragm spaced from said first dia phragm by one of said gaskets.

4c. In a sound box for a phonograph, the combination with a cylindrical casing provided with a constricted sound outlet axially positioned in one end thereof, and

a diaphragm supported by the casing and;

forming a closure for the other end of said casing, of a thin wooden diaphragm supported within the casing parallel to said first diaphragm and between said first diaphragm and the outlet end of said casing, said wooden diaphragm provided with openings therein out of alinemen with said outlet and grooves in both plane surfaces, cut across the grain of the wood.

In a sound box for a phonograph, the combination with a casing provided with a sound outlet and a first diaphragm supported within the casing, of a thin wooden diaphragm, supported within said casing between said first diaphragm and said outlet, said wooden diaphragm provided with openings therein, out of alinement with said outlet, and grooves cut in the plane surfaces thereof across the grain of the wood.

6. In a sound box for a phonograph, the combination with a casing of a diaphragm and an auxiliary woodendiaphragm supported therein and" spaced apart, said wooden diaphragm, provided with four equally spaced openings, adjacent its periphery, and grooves cut in the plane surfaces thereof across the grain of the wood.

7. In a sound box for a phonograph, the

combination with a casin of a dia )hragin' and an auxiliary wooden diaphragm sup,- ported therein, said wooden, diaphragm provided with a series of equally spaced openmgs, adjacent its periphery, and grooves cut in the plane surfaces thereof across the grain of the wood.

8. In a sound box for a phonograph, the combination with a casing ofa diaphragm and an auxiliary wooden, diaphragm supported therein, said wooden diaphragm provided with parallel grooves in both plane surfaces cut across the grain ofthe wood, the grooves on one surface alternating with the grooves on the other surface.

9. In a sound box for a phonograph, the combination with a casing, of a'diaphragm and an'auxiliary wooden diaphragr'n supported therein, said wooden diaphragm provided with grooves in both plane surfaces cut across the grain of the wood.

10. A diaphragm for a phonograph consisting of a thin circular wafer of; wood provided with a series of equally spaced openings adjacent its periphery and-"parallel grooves cut across tlie grain in both ilane surfaces thereof, the rooves in one surface alternating 'with'the grooves in the other surraceL l 11. A diaphragm for a phonograph consisting of a thin circular wafer of wood provided with a series of eq'uallv'spaced openings adjacent its periphery and grooves cut across the grain in both plane surfaces thereof, the grooves in one surface alter nating with the grooves in the other surface.

12. A diaphragm for a phonograph consisting of a thin circular wafer of wood provided with a series of equally spaced openings adiacent its periphery and grooves cut across the grain in both plane surfaces thereof.

with grooves cut across the grain in both plane surfaces thereof.

16(A diaphragm for a honograph consisting of a thin Wafer of wood provided with rectilinear grooves cut across the grain of the Wood.

17. A diaphragm for a phonograph consisting of a thin wafer of Wood provided with grooves out across the grain of the Wood.

In testimony whereof I afiix my signature.

JOSEPH C. KULP.

topics of this patent may be obtained for five cents each,v by addressing the Commissioner of Patents, Washington, I). O." 

